The sample code for each platform is managed as an open source project, licensed under the Apache 2.0 license, and hosted on Google Code's project hosting. A big thank you to the Google Code team for implementing Downloads and Wikis, which were the last missing features we needed before announcing our code sample release.

These projects will issue regular releases which will be listed in the project's download area. Feel free to use the project's issue tracker to log bugs and feature requests, and the project's wiki to document tips and tricks. Contributions to these projects are welcome: if you are interested in contributing, please join the fun and post a proposal to the Developer Forum for that project.

We also released integrations of Google Checkout with the open source shopping carts osCommerce and Zen Cart. These projects are open source as well, and licensed under the GPL 2.0 license.

If you're a merchant contemplating Google Checkout integration, these libraries should make it easy to get started. If you're a developer, e-commerce provider, web designer, or any other entity that maintains relationships with online merchants, you can earn cash for helping your merchants get up and running with Google Checkout: apply for the Google Checkout Merchant Referral Program.

The Google Checkout API developer relations team wishes you a happy holiday season.